Moisture and/or heat exchange device

ABSTRACT

A moisture and/or heat exchange device, for example a plate heat exchanger, a sorption rotor, adsorption dehumidifying rotor or the like, has moisture or heat exchange surfaces, by means of which moisture and/or heat can be introduced into a stream of fluid and/or can be extracted from a stream of fluid and/or can be exchanged between streams of fluid, and a coating, with which the moisture or heat exchange surfaces are coated and which contains a binder and a nano zeolite with a particle size of &lt;1000 nm. In order to ensure permanent attachment of the applied coating, it is proposed that the binder is a polyurethane resin.

The invention relates to a moisture and/or heat exchanger, e.g. a plate heat exchanger, a sorption rotor, an adsorption dehumidification rotor or similar, having moisture or heat-exchange surfaces by means of which moisture and/or heat can be introduced into a fluid flow and/or removed from a fluid flow and/or is exchangeable between fluid flows, and a coating with which the moisture or heat exchange surfaces are coated and that contains a binding agent and a nano-zeolite with a particle size<1000 nm.

It is known from the state of the art for exchange surfaces of this kind to be provided with a coating of nano-zeolite, in order to increase the efficiency of moisture and/or heat exchangers of this kind and in order to ensure permanently reliable operation of such devices.

Problems arose during the operation of moisture and/or heat exchangers of this kind, insofar as permanent adhesion of the coating containing the nano-zeolite to the base surfaces could often not be guaranteed. Moreover, difficulties frequently arose during the coating process itself.

Starting from the state of the art described above, the problem addressed by the invention is that of developing the generic moisture and/or heat exchanger in such a manner that on the one hand the process of coating its moisture and heat exchange surfaces with the coating containing nano-zeolite is made easier and that on the other hand permanent adhesion of the coating applied can be guaranteed.

This problem is solved according to the invention in that the binding agent by means of which the nano-zeolite is attached to the base surface is a polyurethane resin.

During the use of this binding agent, a substantially simpler application of the coating has resulted compared with the state of the art, wherein, moreover, the adhesion of the coating applied to the base surface can be reliably guaranteed for a long period of time.

In order to avoid the transfer of odorous substances or similar, it is advantageous for the nano-zeolite to have a homogeneous pore size distribution with a pore diameter<1.5 nm, preferably 0.4 nm and/or 0.3 nm.

The particles of nano-zeolite may advantageously exist in nano-crystalline form.

The thickness of the coating may lie between 0.2 and 100 or 1 and 20 or 10 and 20 μm (10⁻⁶ m), depending on the requirement profile.

Aluminum, any other suitable metallic or ceramic material, plastic or paper are suitable for use as the material for the embodiment of the moisture or heat exchange surfaces.

According to an advantageous embodiment of the invention, the coating of the nano-zeolite and the binding agent is applied to an unprimed Aluminum surface or one that has not undergone holding primer-forming measures, in particular to an uncleaned and unpretreated aluminum surface.

The binding agent or polyurethane resin is preferably a polyester-based polyurethane resin.

The invention is explained in greater detail below with the help of an embodiment.

A plate heat exchanger, a sorption rotor, an adsorption dehumidification rotor or similar has moisture or heat exchange surfaces that are flat, corrugated or structured in another suitable manner.

In the case of the moisture and/or heat exchanger according to the invention, these surfaces are coated, namely with a coating that contains a nano-zeolite in addition to a binding agent. This nano-zeolite has a particle size<1000 nm and a homogeneous pore size distribution with a pore diameter that is below 1.5 nm, preferably around 0.4 nm or 0.3 nm. In the case of the moisture and/or heat exchanging device according to the invention, the binding agent in the form of a 40% by wt. aqueous dispersion of a polyester-based polyurethane resin containing the nano-zeolite is applied to the moisture or heat exchange surfaces and hardened.

The thickness of the coating is between 0.2 and 100 μm, e.g. between 10 and 20 μm, depending on the requirement profile.

The moisture and heat exchange surfaces may be formed by aluminum. The coating described above is applied to the aluminum without the surface of the aluminum undergoing adhesion-forming measures beforehand. It is even possible for the coating described above to be applied to an uncleaned and un-pretreated aluminum surface.

The coating composed in this manner is suitable for adhering fixedly in the long term. It is permanently dependable. The cost of applying it is comparatively low, as the base surface of the coating does not need to be pretreated or primed. 

1. a plate-type moisture or heat exchanger, a sorption rotor, or an adsorption dehumidification rotor, having moisture or heat-exchange surfaces that can transfer moisture or heat into a fluid flow or extract moisture or heat from a fluid stream or transfer moisture or heat between fluid streams, a coating on the moisture or heat exchange surfaces and that contains polyurethane resin as a binding agent and nano-zeolite particles with a particle size<1000 nm.
 2. The moisture or heat exchanger according to claim 1, wherein the coating of nano-zeolite particles in polyurethane has a homogeneous pore size distribution with a pore diameter<1.5 nm.
 3. The moisture or heat exchanger according to claim 1, wherein the particles of nano-zeolite are in nano-crystalline form.
 4. The moisture or heat exchanger according to claim 1, wherein the thickness of the coating is between 0.2 and
 100. 5. The moisture or heat exchanger according to claim 1, wherein the moisture or heat exchange surfaces are made of aluminum, other suitable metallic or ceramic materials, plastics or paper.
 6. The moisture or heat exchanger according to claim 1, wherein the coating of the nano-zeolite and the polyurethane resin is applied to an unprimed aluminum surface or one that has not undergone holding primer-forming measures.
 7. The moisture or heat exchanger according to claim 1, wherein the binding agent is a polyester-based polyurethane resin. 